共查询到20条相似文献,搜索用时 457 毫秒
1.
Dan Zhu Kirill V. Larin Qingming Luo Valery V. Tuchin 《Laser \u0026amp; Photonics Reviews》2013,7(5):732-757
Tissue optical clearing technique provides a prospective solution for the application of advanced optical methods in life sciences. This paper gives a review of recent developments in tissue optical clearing techniques. The physical, molecular and physiological mechanisms of tissue optical clearing are overviewed and discussed. Various methods for enhancing penetration of optical‐clearing agents into tissue, such as physical methods, chemical‐penetration enhancers and combination of physical and chemical methods are introduced. Combining the tissue optical clearing technique with advanced microscopy image or labeling technique, applications for 3D microstructure of whole tissues such as brain and central nervous system with unprecedented resolution are demonstrated. Moreover, the difference in diffusion and/or clearing ability of selected agents in healthy versus pathological tissues can provide a highly sensitive indicator of the tissue health/pathology condition. Finally, recent advances in optical clearing of soft or hard tissue for in vivo imaging and phototherapy are introduced. 相似文献
2.
Shvachkina M. E. Yakovlev D. D. Lazareva E. N. Pravdin A. B. Yakovlev D. A. 《Optics and Spectroscopy》2019,127(2):359-367
Optics and Spectroscopy - Future development of the method of immersion optical clearing of biological tissues—this method is widely used in the study of the morphology and pathologies of... 相似文献
3.
Boujraf S Luypaert R Shabana W De Meirleir L Sourbron S Osteaux M 《Magnetic resonance imaging》2002,20(4):327-336
The properties of water diffusion in human brain tissue can be characterized by diffusion tensors computed from diffusion weighted magnetic resonance images. Since these properties are strongly determined by the structural and geometrical characteristics of the tissue, the maturation process of white matter and gray matter tissue can be expected to be reflected in these images and derived tensor quantities. The purpose of this work was therefore to study the development of pediatric brain in terms of changes occurring in the observed diffusion behavior. Echo planar diffusion tensor imaging was performed on 22 (10 females and 12 males) full term newborn and infant patients, diagnosed in retrospect as neurologically healthy. The subjects were subdivided in three age categories. A number of quantities based on the diffusion images were calculated for each tissue type and age category, and the ability of these quantities to provide sensitive and consistent information about the tissue differences and evolution was evaluated. The results clearly illustrate that the rotationally invariant quantities (e.g., the highest diffusivity, anisotropy ratio and volume ratio) are superior to the rotationally variant ones (e.g., ADCs measured along the three axes of the magnet) often used in the clinic. On the basis of the anisotropy ratio and the volume ratio indices, a correlation between the white matter maturation and the evolution of the diffusion anisotropy could be established. The same quantities did not exhibit any age dependence for the gray matter tissues. 相似文献
4.
The Maxwell equations are solved for a random discrete medium using the single-scattering approximation and the condition
of immersion in a maximally packed medium. The reflection and transmission factors of plane waves at the interface between
vacuum and a random discrete anisotropic medium are determined. The calculated and experimental results on reflection and
transmission of plane waves near the edge of a forest as an example of natural anisotropy of a random discrete medium are
compared. 相似文献
5.
Luís Oliveira Armindo Lage M. Pais Clemente Valery Tuchin 《Optics and Lasers in Engineering》2009,47(6):667-672
Complete optical characterization of biological tissue is desirable to develop clinical methods using optical technologies. Particularly, to develop optical clearing methods in biological tissues, it is necessary to know the composition of the tissue, the percentage of each constituent and corresponding refractive indexes. To obtain such information for rat muscle, we used a simple method to characterize tissue constituents for both content percentage and refractive index. The study consisted on measuring mass with a precision weighting scale and the refractive index with an Abbe refractometer during tissue dehydration. With the collected data, we used a theoretical model to calculate the refractive index and percentage for both interstitial fluid and solid part of the rat muscle. The results obtained are in good agreement with data published by other authors, and were considered of vital information for the optical clearing studies that we planned to perform. 相似文献
6.
A system of vortices is simulated as an oscillator gas with a certain temperature (rotation rate about axis). In the hydrodynamic
approximation, the conditions at which diffusion anisotropy takes place in such gas are determined. For this case, longitudinal
and transverse diffusion coefficients are determined and shown to be different. The cause of diffusion anisotropy is the Coriolis
force arising due to rotation of vortices (oscillators). 相似文献
7.
L. Trifonyuk W. Baranowski V. Ushenko O. Olar A. Dubolazov Yu. Ushenko B. Bodnar O. Vanchulyak L. Kushnerik M. Sakhnovskiy 《Opto-Electronics Review》2018,26(3):252-259
A new technique of Mueller-matrix mapping of the birefringent structure of biological preparations of human organs tissues is suggested. The algorithms of reconstruction of average values and magnitude of fluctuations of the phase (birefringence) and amplitude (dichroism) of optically anisotropic structure of myocardium and connective tissue component of the vaginal wall histological section are proposed. The magnitudes and ranges of changes in the statistical moments of the 1st-4th order that characterize the distribution of average values and magnitude of fluctuations of birefringence and dichroism of the myocardium and connective tissue of the vaginal tissues histological sections were determined. Joint studies of distributions of the characteristics of phase and amplitude of the anisotropy of myocardium and connective tissue component of the vaginal wall tissues of different states were performed. The cases of various necrotic changes in the myocardium and pathological conditions of the vagina wall (prolapse of the genitals) are examined. Balanced accuracy of the method of Mueller-matrix polarization-phase and diffuse tomography of optically anisotropic polycrystalline networks in the differentiation of necrotic and pathological changes in human organs is determined. 相似文献
8.
We present theoretical fundamentals of polarization and correlation analysis of the optical anisotropy of biological tissues. Results of measurements of coordinate distributions of the complex degree of mutual anisotropy (CDMA) that are formed by birefringent structures of the prostate tissue with benign and malignant changes are compared. Magnitudes and ranges of variation of statistical (the firstto fourth-order distribution moments) and correlation (excess of autocorrelation functions) parameters of the coordinate CDMA distributions of histological sections of the prostate postoperative bioptic material are studied. Objective criteria of the diagnostics of the appearance of pathology and of the differentiation of the degree of its severity are determined. 相似文献
9.
E. A. Genina A. N. Bashkatov M. D. Kozintseva V. V. Tuchin 《Optics and Spectroscopy》2016,120(1):20-27
The technique of -optical clearing of biological tissues- is aimed at improving the quality of visualization of structures hidden deep in tissue. In this study, we measured the diffusion coefficient of glucose in bovine skeletal muscle tissue by optical coherence tomography (OCT) in vitro and determined changes that took place in the imaging contrast of muscle fibers, the optical depth of coherent probing, and detection under the influence of aqueous 40% solution of glucose. It was shown that, within 90 min, when the depth of coherent probing increased by 14%, the contrast of OCT images increased fourfold and the depth of coherent detection of structural elements of the tissue increased by 2.4 times. The diffusion coefficient of glucose in the muscle tissue was (2.98 ± 0.94) × 10-6 cm2/s. 相似文献
10.
É. A. Genina A. N. Bashkatov V. I. Kochubey V. V. Tuchin 《Optics and Spectroscopy》2005,98(3):470-476
The changes in the optical parameters of the human dura mater in the spectral range 400–700 nm caused by the action of an aqueous solution of mannitol with a concentration of 0.16 g/ml are studied in vitro. The diffusion of mannitol into the tissue leads to a partial matching between the refractive indices of the structure-forming elements (the collagen fibrils) and the base substance of the dura mater (the interstitial fluid). As a result, the light scattering by the biological tissue in the entire spectral range under study is decreased, on the average, by a factor of 1.5–2. The immersion of the biological tissue is shown to cause a decrease in the absorption of the dura mater in the range of the blood absorption bands by a factor of 1.2–1.6. The results presented may prove to be useful in the laser therapy and optical diagnostics of brain diseases. 相似文献
11.
The Monte Carlo simulation technique is used to study the dependence of the spatial resolution of a luminescent object inside
the skin on the diffusion time of an immersion fluid. It is shown that, as a result of the surface clearing of the skin, it
is possible to obtain images of luminescent objects at a depth of more than 1 mm in the skin with the spatial resolution of
hundreds of micrometers. Higher spatial resolutions can only be obtained by methods that rapidly change the scattering coefficient
of the medium to a significant depth, for example, by hypodermic injection of an immersion fluid. 相似文献
12.
Ozarslan E Basser PJ Shepherd TM Thelwall PE Vemuri BC Blackband SJ 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2006,183(2):315-323
This report introduces a novel method to characterize the diffusion-time dependence of the diffusion-weighted magnetic resonance (MR) signal in biological tissues. The approach utilizes the theory of diffusion in disordered media where two parameters, the random walk dimension and the spectral dimension, describe the evolution of the average propagators obtained from q-space MR experiments. These parameters were estimated, using several schemes, on diffusion MR spectroscopy data obtained from human red blood cell ghosts and nervous tissue autopsy samples. The experiments demonstrated that water diffusion in human tissue is anomalous, where the mean-square displacements vary slower than linearly with diffusion time. These observations are consistent with a fractal microstructure for human tissues. Differences observed between healthy human nervous tissue and glioblastoma samples suggest that the proposed methodology may provide a novel, clinically useful form of diffusion MR contrast. 相似文献
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15.
The pulsed-gradient spin-echo (PGSE) nuclear magnetic resonance (NMR) method is used for detecting the diffusion of water molecules in biological tissues. Because tissues generally have diffusional anisotropy, their diffusion properties are denoted by a tensor. In this study, we evaluated the diffusional anisotropy and microscopic structure in atrophied skeletal muscles using the PGSE NMR method. The left sciatic nerve was severed in twelve 9-week-old rats. Neurotomy caused neurogenic muscular atrophy at the left gastrocnemius. At 2, 4 and 8 weeks after neurotomy, magnetic resonance signals were selectively acquired from a 2 x 2 x 2 mm(3) voxel, which was located on the left gastrocnemius. The diffusion tensor, the mean diffusivity (MD) and the fractional anisotropy (FA) were calculated from the signals. A theoretical model of the diffusion in muscles was derived from Tanner's equation. The muscle fiber diameter was estimated by fitting the model to the measured signals. The measurements were also performed for normal rats as controls. No significant difference was found in the MD and the estimated intracellular diffusion coefficient between the control group and the denervated group. The denervated group had significantly higher FA compared with the control group (P<.05). The estimated muscle fiber diameter of the denervated group was significantly smaller than the estimated value of the control group (P<.05). These differences were found at 8 weeks after neurotomy. The proposed method is effective for evaluating changes in the microscopic structure of skeletal muscles. 相似文献
16.
Paulsen JL Cho H Cho G Song YQ 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2011,213(1):166-170
NMR can probe the microstructures of anisotropic materials such as liquid crystals, stretched polymers and biological tissues through measurement of the diffusion propagator, where internal structures are indicated by restricted diffusion. Multi-dimensional measurements can probe the microscopic anisotropy, but full sampling can then quickly become prohibitively time consuming. However, for incompletely sampled data, compressed sensing is an effective reconstruction technique to enable accelerated acquisition. We demonstrate that with a compressed sensing scheme, one can greatly reduce the sampling and the experimental time with minimal effect on the reconstruction of the diffusion propagator with an example of anisotropic diffusion. We compare full sampling down to 64× sub-sampling for the 2D propagator measurement and reduce the acquisition time for the 3D experiment by a factor of 32 from ~80 days to ~2.5 days. 相似文献
17.
Asma Hayat Shazia Bashir Muahmamd Shahid Rafique Mahreen Akram Khaliq Mahmood Saman Iqbal Asadullah Dawood Arooj 《Optics and Spectroscopy》2016,120(1):1-8
The optical characteristics of biological tissues sampled from the anterior abdominal wall of laboratory rats are for the first time experimentally studied in a wide wavelength range (350-2500 nm). The experiments have been performed in vitro using a LAMBDA 950 (PerkinElmer, United States) spectrophotometer. Inverse Monte Carlo simulation is used to restore the spectral dependences for scattering and absorption coefficients, as well as the scattering anisotropy factor for biological tissue based on the recorded spectra of diffuse reflection and total and collimated transmissions. 相似文献
18.
Time-resolved polarization-dependent fluorescence of Cybesin in solution and in cancerous and normal prostate tissues were measured. The polarization preservation property of Cybesin in tissue was observed. The fluorescence intensity emitted from a Cybesin-stained cancerous tissue area was found to be much stronger than that from a Cybesin-stained normal tissue area indicating that cancerous prostate tissue takes-up more Cybesin than normal tissue. The polarization anisotropy of Cybesin contained in cancerous prostate tissue was found to be larger than that of Cybesin in normal prostate tissue indicating that a larger degree of polarization was preserved in the Cybesin-stained cancerous tissue due to structures. A static anisotropy component from the emission of cell-bonded Cybesin molecules in tissue and a time-dependent anisotropy component from the emission of un-bonded Cybesin molecules were determined and discussed. The static anisotropy value of Cybesin in stained cancerous tissue was found to be much larger than that in stained normal tissue. The fluorescence polarization difference imaging technique based on the polarization preservation of Cybesin was used to enhance the image contrast between cancerous and normal prostate tissue areas. 相似文献
19.
Félix Fanjul-Vélez 《Optics Communications》2010,283(22):4525-4856
The characterization of biological tissues by optical techniques provides several advantages over other techniques. Optical techniques enable to perform high resolution and contrast imaging, in a non-invasive way and with no-contact. Biological tissues are turbid media that strongly scatter light. The ultrastructure of some tissues makes them present a certain degree of anisotropy. Both scattering and anisotropy affect light polarization. Some pathologies alter these characteristics of the tissue. As a consequence polarized light can be used to extract additional information and achieve a better diagnosis.In this work, Group Theory is applied to analyse the polarization behavior of several samples. Firstly, the Mueller matrix for each sample is measured. Then, the Mueller Coherency matrix is obtained by means of the SU(4)-O + (6) homomorphism. Finally, the target decomposition theorem is applied by analyzing the eigenvalues and eigenvectors, and subsequently the different polarimetric effects are separated. In this way, the contrast of tissue imaging can be increased. This analysis is applied to biological tissue phantoms, which consisted on glucose suspensions of polystyrene spheres with different scatterer concentrations. Their behaviour can be modeled by means of single or multiple scattering depending on the concentration, either in the Rayleigh or Mie regimes. The same procedure could be used in a wide range of applications, like the study of cancerous cells that grow without control in cell cultures, or erythrocytes monitoring in anemia. The technique also has a great potential to be applied in Polarization Sensitive Optical Coherence Tomography (PS-OCT). 相似文献